elevation, by the action of the pressure of the atmosphere in forcing the liquid up the shorter branch of
the pipe immersed in it, while the continued excess of weight of the liquid in the longer branch (when
once filled) causes a continuous flow. The flow takes place only when the discharging extremity of the
pipe ia lower than the higher liquid surface, and when no part of the pipe is higher above the surface
than the same liquid will rise by atmospheric pressure; that is, about 33 feet for water, and 30 inches for
mercury, near the sea level.
2. (Zoöl.) (a) One of the tubes or folds of the mantle border of a bivalve or gastropod mollusk by which
water is conducted into the gill cavity. See Illust. under Mya, and Lamellibranchiata. (b) The anterior
prolongation of the margin of any gastropod shell for the protection of the soft siphon. (c) The tubular
organ through which water is ejected from the gill cavity of a cephaloid. It serves as a locomotive organ,
by guiding and confining the jet of water. Called also siphuncle. See Illust. under Loligo, and Dibranchiata.
(d) The siphuncle of a cephalopod shell. (e) The sucking proboscis of certain parasitic insects and
crustaceans. (f) A sproutlike prolongation in front of the mouth of many gephyreans. (g) A tubular
organ connected both with the esophagus and the intestine of certain sea urchins and annelids.
3. A siphon bottle.
Inverted siphon, a tube bent like a siphon, but having the branches turned upward; specifically (Hydraulic
Engineering), a pipe for conducting water beneath a depressed place, as from one hill to another
across an intervening valley, following the depression of the ground. — Siphon barometer. See under
Barometer. — Siphon bottle, a bottle for holding aërated water, which is driven out through a bent tube
in the neck by the gas within the bottle when a valve in the tube is opened; — called also gazogene,
and siphoid. — Siphon condenser, a condenser for a steam engine, in which the vacuum is maintained
by the downward flow of water through a vertical pipe of great height. — Siphon cup, a cup with a
siphon attached for carrying off any liquid in it; specifically (Mach.), an oil cup in which oil is carried over
the edge of a tube in a cotton wick, and so reaches the surface to be lubricated. — Siphon gauge.
See under Gauge. — Siphon pump, a jet pump. See under Jet, n.
Siphon
(Si"phon) v. t. (Chem.) To convey, or draw off, by means of a siphon, as a liquid from one
vessel to another at a lower level.
Siphonage
(Si"phon*age) n. The action of a siphon.
Siphonal
(Si"phon*al) a. Of or pertaining to a siphon; resembling a siphon.
Siphonal stomach (Zoöl.), a stomach which is tubular and bent back upon itself, like a siphon, as in the
salmon.
Siphonarid
(Si`pho*na"rid) n. (Zoöl.) Any one of numerous species of limpet-shaped pulmonate gastropods
of the genus Siphonaria. They cling to rocks between high and low water marks and have both lunglike
organs and gills. — Si`pho*na"rid, a.
Siphonata
(||Si`pho*na"ta) n. pl. [NL.] (Zoöl.) A tribe of bivalve mollusks in which the posterior mantle
border is prolonged into two tubes or siphons. Called also Siphoniata. See Siphon, 2 (a), and Quahaug.
Siphonate
(Si"phon*ate) a.
1. Having a siphon or siphons.
2. (Zoöl.) Belonging to the Siphonata.
Siphonet
(Si"phon*et) n. (Zoöl.) One of the two dorsal tubular organs on the hinder part of the abdomen
of aphids. They give exit to the honeydew. See Illust. under Aphis.
